1. Field of the Invention
The present invention relates generally to the fields of cancer treatment. More particularly, it concerns non-invasive methods for determining the effectiveness of cancer treatment.
2. Description of Related Art
Methods of treating cancer include radiation therapy, surgery and chemotherapy. While chemotherapy has been widely employed, the indicated chemotherapeutic agents or combinations thereof are not always successful in achieving remission. All too often, an indicated course of chemotherapy is initiated, only to result in a failure to achieve remission of the cancer. The chemotherapy may continue for weeks or even months before the physician may conclude that the treatment is unsuccessful, and that alternative chemotherapeutic agents are warranted. Valuable time is lost during the period of ineffective chemotherapy.
Tumor cells generally express more growth factor receptors than normal cells. Chemotherapeutic drugs typically used to treat cancers and metastases are those that inhibit phosphorylation of the growth factor receptors. Some examples are drugs such as Novartis PKI166 or the Mendelsohn C225 antibody that inhibit phosphorylation of the epidermal growth factor receptor (EGF-R). Currently the only way to assay effectiveness of these treatment types is by performing biopsies, which is an invasive procedure and can result in complications from anesthesia and can further cause infections in the already immunocompromised patients. For example, Gewirtz and Calabretta (U.S. Pat. No. 5,427,916) discuss a method for predicting the effectiveness of antineoplastic therapy by comparing the expression of growth-regulated genes in neoplastic cells taken from a patient before and shortly after the initiation of therapy. Thus, an effective, non-invasive method for assessing the effectiveness of anticancer treatments is required.